IUBMB Enzyme Nomenclature


Accepted name: acyl-Kdo2-lipid IVA acyltransferase

Reaction: a fatty acyl-[acyl-carrier protein] + an α-Kdo-(2→4)-α-Kdo-(2→6)-(acyl)-[lipid IVA] = an α-Kdo-(2→4)-α-Kdo-(2→6)-(acyl)2-[lipid IVA] + an [acyl-carrier protein]

For diagram of reaction click here

Glossary: Kdo = 3-deoxy-D-manno-oct-2-ulopyranosylonic acid
a lipid IVA = 2-deoxy-2-{[(3R)-3-hydroxyacyl]amino}-3-O-[(3R)-3-hydroxyacyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxyacyl]-2-{[(3R)-3-hydroxyacyl]amino}-1-O-phospho-α-D-glucopyranose
an α-Kdo-(2→4)-α-Kdo-(2→6)-(acyl)-[lipid IVA] = 3-deoxy-α-D-manno-oct-2-ulopyranosyl-(2→4)-3-deoxy-α-D-manno-oct-2-ulopyranosyl-(2→6)-2-deoxy-2-{[(3R)-3-(acyloxy)acyl]amino}-3-O-[(3R)-3-hydroxyacyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxyacyl]-2-{[(3R)-3-hydroxyacyl]amino}-1-O-phosphono-α-D-glucopyranose
an α-Kdo-(2→4)-α-Kdo-(2→6)-(acyl)2-[lipid IVA] = 3-deoxy-α-D-manno-oct-2-ulopyranosyl-(2→4)-3-deoxy-α-D-manno-oct-2-ulopyranosyl-(2→6)-2-deoxy-2-{[(3R)-3-(acyloxy)acyl]amino}-3-O-[(3R)-3-(acyloxy)acyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxyacyl]-2-{[(3R)-3-hydroxyacyl]amino}-1-O-phospho-α-D-glucopyranose

Other name(s): lpxM (gene name); MsbB acyltransferase; myristoyl-[acyl-carrier protein]:α-Kdo-(2→4)-α-Kdo-(2→6)-(dodecanoyl)-lipid IVA O-myristoyltransferase; tetradecanoyl-[acyl-carrier protein]:dodecanoyl-Kdo2-lipid IVA O-tetradecanoyltransferase; lauroyl-Kdo2-lipid IVA myristoyltransferase

Systematic name: fatty acyl-[acyl-carrier protein]:α-Kdo-(2→4)-α-Kdo-(2→6)-(acyl)-[lipid IVA] O-acyltransferase

Comments: The enzyme is involved in the biosynthesis of the phosphorylated outer membrane glycolipid lipid A. It transfers an acyl group to the 3-O position of the 3R-hydroxyacyl already attached at the 2-O position of the non-reducing glucosamine molecule. The enzyme from the bacterium Escherichia coli is specific for myristoyl (C14) acyl groups, giving the enzyme its previous accepted name. However, enzymes from different species accept highly variable substrates.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:


1. Clementz, T., Zhou, Z. and Raetz, C.R. Function of the Escherichia coli msbB gene, a multicopy suppressor of htrB knockouts, in the acylation of lipid A. Acylation by MsbB follows laurate incorporation by HtrB. J. Biol. Chem. 272 (1997) 10353-10360. [PMID: 9099672]

2. Dovala, D., Rath, C.M., Hu, Q., Sawyer, W.S., Shia, S., Elling, R.A., Knapp, M.S. and Metzger, L.E., 4th. Structure-guided enzymology of the lipid A acyltransferase LpxM reveals a dual activity mechanism. Proc. Natl. Acad. Sci. USA 113 (2016) E6064-E6071. [PMID: 27681620]

[EC created 2014, modified 2021]

Return to EC 2.3.1 home page
Return to EC 2.3 home page
Return to EC 2 home page
Return to Enzymes home page
Return to IUBMB Biochemical Nomenclature home page